Single quantum dot nanowire photodetectors

We report InP nanowire photodetectors with a single InAsP quantum dot as light absorbing element. With excitation above the InP band gap, the nanowire photodetectors are efficient (quantum efficiency of 4%). Under resonant excitation of the quantum dot, the photocurrent amplitude depends on the linear polarization direction of the incident light. The photocurrent is enhanced (suppressed) for a polarization parallel (perpendicular) to the axis of the nanowire (contrast 0.83). The active detection volume under resonant excitation is 7x10(3) nm(3). These results show the promising features of quantum dots embedded in nanowire devices for electrical light detection at high spatial resolution. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3484962]